Geochemistry and genesis of metamorphosed volcanic rocks in the Kholodnikan greenstone belt,southern Aldan Shield

The Kholodnikan Complex consists of two units: lower volcanic and upper volcanic-sedimentary. The distributions of major and trace elements suggest that the protoliths of the lower unit were volcanics of the komatiite-tholeiite series (komatiite-basalt association) and those of the upper unit were volcanics of the calc-alkaline series (andesite-dacite-rhyolite association). The model assumed for the genesis of these associations involves two stages: (1) decompression-induced partial melting of the material of an ascending mantle plume with the derivation of melts of the komatiite-basalt association and (2) derivation of volcanic rocks of the andesite-dacite-rhyolite association via the partial melting of various rocks in the basement of the Aldan Shield under the effect of the heat of the ascending mantle plume. The magmatic protoliths of the Kholodnikan Complex were formed in the Paleoproterozoic at 2.41 Ga.